大约有 46,000 项符合查询结果（耗时：0.0466秒） [XML]
Is there any difference between “foo is None” and “foo == None”?
... Hmmm, I think your link changed, unless you were interested in how to call external functions from python
– Pat
May 4 '12 at 20:39
...
Which characters need to be escaped when using Bash?
...h but also bash.
1. Put the whole string in single quotes
This works for all chars except single quote itself. To escape the single quote, close the quoting before it, insert the single quote, and re-open the quoting.
'I'\''m a s@fe $tring which ends in newline
'
sed command: sed -e "s/'/'\\\\'...
How to solve PHP error 'Notice: Array to string conversion in…'
...n $_POST['C']. So when you echo that, you are trying to print an array, so all it does is print Array and a notice.
To print properly an array, you either loop through it and echo each element, or you can use print_r.
Alternatively, if you don't know if it's an array or a string or whatever, you c...
How to save an HTML5 Canvas as an image on a server?
I'm working on a generative art project where I would like to allow users to save the resulting images from an algorithm. The general idea is:
...
How do you validate a URL with a regular expression in Python?
...he result of parsing gives you a netloc or path you don't like, you could call that "invalid".
– S.Lott
Jun 29 '09 at 20:44
2
...
How can I programmatically check whether a keyboard is present in iOS app?
... responder. I have a view controller with multiple child view controllers, all of which contain UITextFields. Using this method, i cannot tell from my parent view controller whether the keyboard is shown. The only reliable way is to use the notification method explained in the other answers
...
Remove last item from array
..., -1) will not. Pop is of course faster but may not be always suitable for all needs.
– adelriosantiago
Sep 23 '17 at 0:40
...
Django rest framework nested self-referential objects
... the `subcategories` field
return CategorySerializer()
Actually, as you've noted the above isn't quite right.
This is a bit of a hack, but you might try adding the field in after the serializer is already declared.
class CategorySerializer(serializers.ModelSerializer):
parentCat...
What is the difference between shallow copy, deepcopy and normal assignment operation?
...ble towards the existing object. The docs explain the difference between shallow and deep copies:
The difference between shallow and deep copying is only relevant for
compound objects (objects that contain other objects, like lists or
class instances):
A shallow copy constructs a new...
Determine function name from within that function (without using traceback)
... Combining @CamHart's approach with @Yuval's avoids "hidden" and potentially deprecated methods in @RoshOxymoron's answer as well as numerical indexing into the stack for @neuro/@AndreasJung's answer: print(inspect.currentframe().f_code.co_name)
– hobs
Mar 1...